DESCRIPTION: The overall goal of this project is to characterize organic solvent exposure among a cohort of commercial fishers and determine the association between this exposure and neuropsychological and neurobehavioral tests scores. Although commercial fishing is among the most hazard industries in the United States (Myers et at. 1994) little is known about the health hazards in this occupational group. However, despite the lack of information on health hazards in this industry, fishers are known to be exposed to a variety of organic solvents including evaporative emissions from fuel and fuel exhaust, styrene and acetone during fiberglass work, paints and tars for waterproofing their traps. These chemicals have been associated with decrements in neurobehavioral measures of memory and psychomotor function (Baker et al. 1994). In order to achieve the project goal, repeat measures of personal exposure to organic solvents will be made and combined with data from an ongoing cohort study of 225 fishers. Fisher participants in the cohort study receive a battery of neuropsychological and neurobehavioral tests at baseline and every six months during the follow-up period. In addition, a wealth of information on occupational activities and personal factors that may be related to poor performance on neuropsychological tests is collected. The analytic strategy that will be employed for this project involves the use of mixed model methods to identify control options and determine homogenous exposure groups. Once homogenous exposure groups are defined, exposure levels can be assigned to each fisher in the cohort. Statistical analyses will generate the following measures of association or effect for each neuropsychological and neurobehavioral test result: (1) mean test score and standard deviation in different exposure groups; (2) the slope and correlation coefficient describing the association between exposure and test score; and (3) an odds ratio estimating the relative risk of an abnormal test score across exposure groups. Both the cumulative exposure and the timing of exposure on outcome measures will be evaluated. In addition, the effect of individual solvents and the combined effect of multiple solvents will be determined. The main strength of this study involves its use of a rich database of exposure and outcome data from an ongoing study of commercial fishers. The exposure assessment piece proposed in this project is an ideal addition to the cohort study and will provide valuable information for evaluating the risks from continuous and intermittent exposure to commonly used organic solvents.